[RugnirViking]

To be fair, B1 and especially B2 are not trivial requirements. A1 you will "pick up" like you say, but it's easy to fall into a trap of remaining around A2 without sustained effortful studying. (If you try to do it through just interacting with natives with no structure it's common to fossilize mistakes which take much longer to fix, or even just become permanent)

Personally I've gotten to B2 (not Germany) which is enough for most purposes, but it would have been very possible to get stuck in a rut.

It's very common for couples that move here for one to have a job, and the other to spend some months unemployed looking for a job. It's generally observed that those that have the job learn the job much slower and get stuck, and the ones that spend time at home and looking have much better outcomes longer term

[sigmoid10]

B1 to B2 is a big step. Bigger than A1-2 to B1. B1 is basically just understanding people who speak slowly and clearly and being able to participate in everyday life situations. So a very gradual progression. B2 is already being able to do professional work in that language. This is what will take considerable time and active study. But it is also not a requirement for naturalisation in most countries. And many natural born citizens also never reach C1-2 level of proficiency either. So if you're B2, you may as well be counted as fully integrated.